Braking system



yRe 22,802

0*- 15, H BAADE BRAKING SYSTEM 2 Sheets-Sheet 1 Original Filed Jan. 3l, 1958 INVENI'OR. zum nnor.- 6e# ll'l you Ill. I I i I I l l I I I l .lllfllll vv l swwin v N QE b Nmw .fY ,3Q NQ wmv) UYW\ ..N|,. ;Ici,i.. l, QQ@ 4 lllwi N2 |I4 l I llillll/ wenn! u A C HIMWMB fr.. im. i 1I 1|! Y V1 wm ATTORNEY.

ott. 15, 1946. I H; BAADE I BRKING'-SYSTE 2 sheets-smeet 2 Original Filed Jan.- 551, 1938 OR. HENRY Bswnozv BY WML t? 60%- ATTORNEY.

Ressued Oct. 15, 1946 BRAKING SYSTEM Henry Baade, Ypsilanti, Mich., assignor to Bendix Products Corporation, South Bend, Ind., a corporation of Indiana Original No. 2,215,602, dated September 24, 1940,

Serial No. 187,905, January 31, 1938. Application for reissue July 25, 1941, Serial No. 404,057

(Cl. 18S- 3) 17 Claims.

This invention relates to brakes and more particularly to trailer brakes operated by power.

An object of the invention is to provide means for operating trailer power brakes from a touring vehicle equipped with hydraulic brakes.

Another object is to provide means for controlling vacuum-suspended vacuum brake cylinders on a trailer vehicle from a touring vehicle having hydraulically operated brakes.

Still another object is to provide means for controlling atmospheric-suspended vacuum brake cylinders on a trailer vehicle having hydraulically operated brakes.

Another object is to provide means for controlling a vacuum brake cylinder in accordance with the pressure in a hydraulic brake system.,

Yet another object is to provide means for controlling a differential air pressure cylinder by means of the hydraulic pressure in a hydraulic brake system.

I prefer to accomplish these objects by providing, generally on the touring or tractorvehicle, a control valve adapted to control the differential air pressures applied to a power cylinder for operating the trailer brakes positioned on the trailer vehicle, which valve is operated by means of a hydraulic motor cylinder operatively connected with the pressure lines of the hydraulic brake system of the tractor Vehicle.

I prefer to provide a valve having pressure responsive means responsive to the controlled pressure in the power brake cylinder, which pressure responsive means reacts against the force of the hydraulic actuating cylinder so that the hydraulic pressure and the controlled pressure are substantially proportionate.

The above and other objects and desirable particular constructions and arrangements of parts will be apparent upon reference to the following detailed description of several embodiments of my invention shown in the accompanying drawings in which:

Figure 1 is a diagrammatic plan view of tractorf another type of valve suitable for use in the arrangement of Figure 1; and

Figure 6 is a longitudinal sectional View of another type of valve suitable for use in the arrangement of Figure 2.

Figure 1 shows a touring vehicle, here illustrated as an automobile I6, having axles I2 on which are mounted wheels I4 and brakes I6. The automobile is provided with a hydraulic master cylinder I8 operated by a foot pedal 20 or corresponding device. Fluid from the master cylinder I8v is delivered by copper tubing 22 or the like and flexible hose 24 to the brakes I6 to operate them. Another tube 24a delivers fluid from the master cylinder to my novel control valve 26. The automobile I0 has the usual internal combustion engine 28 with an induction pipe or intake manifold 30 which provides a source of vacuum. A conduit 32 connects this source of vacuum to my novel valve 26 and the controlled pressure from my novel valve is conducted to the rear of the vehicle by a conduit 34 terminating at a cut-off valve 36.

Attached to the rear of the automobile I0 is a towed vehicle or trailer 38 having an axle 40 on which are mounted wheels 42 and brakes 44. The brakes may be operated by Bowden cables 46, or the like, connected to atmosphericsuspended vacuum cylinders 48 .secured to the structure of the trailer. The cylinders 48 have vacuum hoses 50 connected thereto leading to a common hose 52 extending forwardly of the vehicle and connected by a flexible hose 54 to the tractor vehicle controlled pressure conduit 34 through the cut-oir valve 36, which, of course, is opened when the trailer is attached. My novel valve 26 is shown in detail in Figure 3. It comprises a pair of casing shells 56 and 58 having clamped between them a diaphragm 60, having an annular ringof perforations 62. I'he lower shell 56 and diaphragm 60 form an air chamber 64 communicating with an air cleaner 66 by means of a port 68. The diaphragm and upper casing shell 58 form two chambers separated at times by an annular wall 10. The outer chamber I2 is a vacuum chamber communicating with the conduit 32 by a port 14 and the inner chamber 16 is a controlled pressure chamber communicating with the conduit 34 by a port 18.

A plunger is secured to the center of the diaphragm 6I] and extends through suitable packings out of the casing shell 58. Secured to the plunger on opposite sides of the diaphragm are a pair of valve discs 82 and 84. The disc 82 is on the air chamber side, has perforations corresponding to the perforations 62 of the diaphragm EEE), and is of such diameter that, when the plunger 88 is moved upwardly this disc presses the diaphragm against the edge of the annular wall 18 separating the two chambers 12 'and 15. The other disc 84 is on the opposite side of the diaphragm, is not perforated, is provided with an annular edge adapted to engage and seal against the diaphragm radially outwardly of the perforations 62, and is of slightly less diameter than the annular wall 18. When the plunger 8|) is raised to its extreme position, the annular diaphragm engaging edge of the disc 84 is lifted free of the diaphragm.

A pair of brackets 86 secured to thecasing members carry a hydrauliccylinder 83' having a piston 90 engaging the plunger 8l). The cylinder is provided with an inlet port 92 receiving the conduit 24a, and the usual bleed screw 94. Compressed between a wash er S5 abutting against adjusting nuts S8 threaded on the plunger 88, and the outer surface of the casing shell 58 is a coil spring |93 which normally urges the plunger up- Wardly.

In operation it will be noted that with the plunger 89 in its normal position as determined by the spring |90, air at atmospheric pressure enters-the air chamber |54 from the air cleaner .e5 through the port 6B, and passes from the air chamber 64 into the controlled pressure chamber 84 through thepreforations 62 in the diaphragm 6l! and under the edge of the valve disc 8. Consequently the pressure in the controlled pressure conduit 34, the flexible hose 54, the conduits 5d and 52 and the cylinders 48 is atmospheric and the trailer brakes 44 are released.

' New when the driver of the automobile i8 applies the brakes It of the automobile by pressing on the foot pedal 28, hydraulic pressure is created in the line 24a which acts 0n the piston 98 to force the plunger downwardly Iwhen the force' on the piston exceeds the force of the lspring Itl. When this occurs the valve disc 84 seats on the diaphragm E0, closing communication between' the vair chamber 64 and thecontrolled pressure chamber 16 through the ports 62 then the diaphr'agm 83 is lifted from the edge ofthe annular wall 1!) permitting 'communication between the vacuum chamber 12. This vcommunication with the vacuum chamber withdraws air from the con-f trolled pressurek chamber 15, the conduit 34, hose 54, conduits 5|! and 52, and the cylinders 48 thereby applying the trailer brakes 44. I

The vacuum'in chamber 16 reacts on the diaphragm 60 in opposition to the hydraulic'pressure on the piston 9) and, if this pressure i's not too great (i. e. if the brakes are applied lightly) the valve will move back to a lapped position where-r inthe diaphragm is in contact with both the annular wall and the valve disc 84. Then, ifV the' brakes are applied more strongly or are slightly released, communication is reestabli-shed in one direction or the other to increase or decrease the amount Vof vacuum in the controlled pressure chamber 16.

It Iwill be observed that by using my novel defA jority of modern passenger automobiles are equipped with hydraulic brakes, but I do not desire to limit myself to this application solely.

In the arrangement of Figures 2 and fl coiree 'spending parts are designated by the same reference numerals plus |66. Referring to the valve |26 of Figure 4, the casing shells |56 and |53 are arranged in inverse positions to those of the valve 25 of Figure l. With this valve the vacuum chamber |12 and the controlled pressure chamber |16 are normally in communication so that vacuum is transmitted through the conduit |34, the flexible hose |54 and the conduits |53 and |52. The conduits |56 yare connected to the rear ends of the cylinders |48, and an extension of the vacuum line |32 comprising a conduit l32c, a flexible hose |32b, and conduits |820 and are 15 connected to the front ends of the cylinders M8. When the valve IZB-is operated air is admitted to the controlled pressure chamber and transmitted through the lines to the rear of the cylinders M8 thereby applying the brakes. This system is called a vacuum-suspended system while that of Figure lfis called an Vatincspheric-suspended 'system. InFigure 5 I have shown arnodiiied valve for the atmospheric suspended system of Figure l. In tlrfs ligure parts corresponding to parts cflllgure l are designated by the same reference numeral plus 2(18. In this valve the plunger 23D `is provided with a reduced portion 28de, 'a cut-away portion 23819, and a longitudinal groove 23de. With the plunger in' its normal position vair is transmitted through the air portl past the reduced and out-away portions 285m and 28511) of the plunger 288 to the controlled pressure port Y 218; When hydraulic pressure acts on the piston 35 288 the plunger 280 is moved downwardly so that the airport 288 is rst cut oli and then the vacuum port 214 is'opened andp'ut into communica-v` tion with the controlled pressureport 218. The I pressure in the controlled pressure port 218 is at 4'0` all times transmitted through the slot 232e to the controlled pressurechamber 216 ,where it reacts upon the upper face of the diaphragm 2GB to balance the force of the piston 29d in the .same manner asdcscribed with relation to the valve 2E,

for use in a vacuum-suspended system such as Figure 2,. I n this modification parts corresponding rto parts of Figure l are designatedl bythe same reference numerals plus .3515. l In this'mcdicaticn the valve elements comprise a plungers secured to the diaphragm Stil, a oating' lever 338e engagedby the plunger and engaging a` pair of poppetfvalves 38l|band 388e respectively adapted to close the air ports .358 and the vacuum port 311i. v the stem of the valve @dub insures that one valve closes before .the other opens and vice versa. The plunger 388 is normally urged upwardly by the spring 48|! in which position the valve 388C is 60 iifteii admitting vacuum from ine pori 314 to the controlled pressure chamber 316.- When the valve is operated by forcing the plunger downwardly, valve 389e first closes, cutting 01T the vacuum, and-y 6'5 then valve 38019 opens, admitting air to the controlled pressure chamber. Vacuum is normallyv present in the chamber 312 on the upper side ofthediaphragm, a' port 314e being provided for this purpose'. When air` is admitted to the) conm trolledpressure lchar'nber 316 it reacts againstthe diaphragm 360 in opposition to the force of the piston 390 thereby providing proportionate braking'on the trailer as previously described.

. While Ihave described severarembodiments of my invention, ii iii not'my intention i0 be' limited l The valve of Figure' 6 is a modification suitable A biasing spr-ingd on.

to those embodiments or otherwise than by the termsl of the appended claims.

I claim:

1. In combination, a tractor, a trailer, brakes lon each, hydraulic pressure creating means for actuating the tractor brakes, differential air pressure operating means for the trailer brakes, a source of differential air pressure, a valve for controlling said differential air pressure, hydraulic pressure actuating means on said valve, connections between the hydraulic pressure creating means and the hydraulic pressure actuating means, and connections between said valve and said source of differential air pressure and between said valve and said diiferential air pressure operating means.

2. In combination, a tractor, a trailer, brakes on each, hydraulic pressure creating means for actuating the tractor brakes, differential air pressure operating means for the trailer brakes, a source of differential air pressure, a valve for controlling said differenti-al air pressure, hydraulic pressure actuating means on said valve, connections between the hydraulic pressure creating means, and the hydraulic pressure actuating means, and connections between said valve and said source of differential air pressure and between said valve and said differential air pressure-operating means, said valve having a pressure responsive element reacting against said hydraulic pressure actuating means.

3, In combination, a tractor, a trailer, brakes on each, hydraulic pressure creating means for .actuating the tractor brakes, differential air pressure operating means for the trailer brakes, a source of differential air pressure, a valve for controlling said differential air pressure, hydraulic pressure actuating means on said valve, connections between the hydraulic pressure creating means and the hydraulic pressure actuating means, and connections between said valve and said source of differential air pressure and between said valve and said differential air pressure operating means, said valve having a spring and a pressure responsive element reacting against said hydraulic pressure actuating means.

4. A combination braking system for vehicles comprising hydraulic brakes and differential air pressure operated brakes, a source of differential air pressure, connections between said source and said differential air pressure operated brakes, a control valve in said connections, and means in said valve responsive to the pressure in the hydraulic brakes for actuating said valve.

5. A combination braking system for vehicles comprising hydraulic brakes and differential air pressure operated brakes, a source of differential air pressure, connections between said source and said differential air pressure operated brakes, a control valve in said connections, means in said valve responsive to the pressure in the hydraulic brakes for actuating said valve, and means in said valve responsive to the differential air pressure opposed to said Iirst named means.

6. A combination braking system for vehicles comprising hydraulic brakes and differential air pressure operated brakes, a source of differential air pressure, connections between said source and said differential air pressure operated brakes, a control valve in said connections, means in said valve responsive to the pressure in the hydraulic brakes for actuating said valve, and a spring op- 'posed to said first named means.

7. A combination braking system for vehicles comprising hydraulic brakes and differential air 6 pressure'operated brakes, a source of differenta air pressure, connections between said sourcev and said differential air pressure operated brakes, a control valve in said connections, meansv insaid valve responsive to the pressure in the hydraulic brakes for actuating said valve, a spring opposed to .said first named means, and means for adjusting the force exerted by said spring.

8. In combination, a tractor, a trailer, jbrakes on each, hydraulic pressure creating meansl for actuating thetractor brakes,vacuum cylinders for operating the trailer brakes, a source Iofvacuum, a valve for controlling the vacuum, hydraulic pressure actuating means on said valve, connections between the hydraulic pressure creating means and the hydraulic pressure; actuating means, and connections betweeny said valve and said source of vacuum and between said-valve said vacuum cylinders. v

Q In combination, a tractor, a trailer, brakes on each, hydraulic pressure creating means for actuating the tractor brakes, vacuum cylinders for operating the trailer brakes, asource of vacuum, a valve for controlling the vacuum, hydraulic pressure actuating means on said valve, connections between the hydraulic pressure creating means and the hydraulic pressure actuating means, and connections between said valve and said source of vacuum and between saidvalve and said vacuum cylinders, said vacuum cylinders being of the atmospheric-suspended type.

10. In combination, a tractor, a trailer, brakes on each, hydraulic pressure creating means for actuating the tractor brakes, vacuum cylinders for operating the trailer brakes, a source of vacuum, a valve for controlling the vacuum, hydraulic pressure actuating means on said valve, connections between the hydraulic pressure creating means and the hydraulic pressure actuating means, and connections between said valve and said source of vacuum and between said valve and said vacuum cylinders, said vacuum cylinders being of the vacuum suspended type.

11. In combination, a tractor, a trailer, brakes on each, hydraulic pressure creating means for actuating the tractor brakes, vacuum cylinders for operating the trailer brakes, a source of vacuum, a valve for controlling the vacuum, hydraulic pressure actuating means on said valve, connections between the hydraulic pressure creating means and the hydraulic pressure actuating means, and connections between said valve and saidk source of vacuum and between said valve and said vacuum cylinders, said vacuum cylinders being of the atmospheric-suspended type, and said Valve having a vacuum responsive element opposed to said hydraulic pressure actuating means.

12. In combination, a tractor, a trailor, brakes on each, hydraulic pressure creating means for actuating the tractor brakes, vacuum cylinders for operating the trailor brakes, a source of vacuum, a valve for controlling the Vacuum, hydraulic pressure actuating means on said valve, connections between the hydraulic pressure creating means and the hydraulic pressure actuating means, and connections between said Valve and said source of vacuum and between said valve and said Vacuum cylinders, said vacuum cylinders being of the Vacuum suspended type, and said valve having an air pressure responsive element opposed to said hydraulic pressure actuating means.

13. A combination braking system comprising hydraulically operated brakes and pneumatically operated brakes, a hydraulically operated element operated by pressure on the hydraulically operated brakes, valve elements moved by said hydraulically actuated element for controlling the admission of different air pressures to a controlled pressure chamber to operate the pneumatica-ily operated brakes and an air pressure responsive element in said chamber constructed and arranged to oppose the force of the hydraulically actuated element and increase the reaction force of the hydraulically operated brakes.

14. A combination braking system comprising pressure operated brakes, hydraulic means for creating brake applying pressure, differential air pressure means for creating brake applying pressure, a source of differential air pressure, a connection between said source and said diierential air pressure means, a valve in said connections adapted to control the opening and closing of said connection, and means responsive to the pressure in the hydraulic means for actuating said valve.

l5. A braking system comprising pressure operated brakes, hydraulic means for creating brake applying pressure, differential air pressure means for creating `brake applying pressure, a source of differential air pressure, a connection between said source and said diierential air pressure means, a valve in said connection adapted to control the opening and closing of said connection,

ating said valve, and a spring opposed to said Valve actuating means.

1'7. A combination braking system comprising hydraulic means for operating brakes and differential air pressure operated means for operating brakes, a source of differential air pressure, a connection between said source and said differential air pressure operated means, a Valve in said connection adapted to control the opening and closing of said connection, means responsive to the pressure in the hydraulic means for actuating said Valve, a spring opposed to said valve actuating means, and means for adjusting the force exerted by said spring.

HENRY BAADE. 

